With the development of network technologies and applications, in particular the development of cloud computing related IaaS (Infrastructure as a Service), PaaS (Platform as a Service) and SaaS (software as a Service), it becomes a relatively typical service needs to provide different network services in data center to different users. Because these services are generally facing to public users, and typically there are thousands, tens of thousands, or even hundreds of thousands of computers in the data center, the number of users that can be supported is relatively large, that is, in the data center, it needs to support a large number of virtual networks and provide mutually isolated network services for different users.
In the data center, a variety of technologies can be used to provide isolation between these different networks, for example, the VLAN (Virtual Local Area Network) can be used to isolate, or the L3/L2 VPN (Virtual Private Network) can be used to implement. However, due to inherent limitations of these technologies, it is difficult to obtain a good scalability. Therefore, the network virtualization technology over Layer 3 (L2) overlay, namely NVO3 (L2 “Network Virtualization Over L3” overlay, shorted as network virtualization over L3), is developed, and the basic idea of this network virtualization technology is that, virtual network messages are tunnel re-encapsulated by introducing the tunneling technology so as to distinguish different virtual networks through different tunnels. FIG. 1 is a schematic diagram of the network structure of a data center, as shown in FIG. 1, the introduction of NVE (Network Virtualization Edge) into the data center realizes the tunnel encapsulation of the virtual network, wherein, the NVE can be a Hypervisor, an access switch or a router, and so on.
The abovementioned tunnels can be defined and distinguished through a typical 24-bit field, so as to obtain up to sixteen million or so virtual networks, which can meet the needs of a large number of users and solve the problem of scalability.
However, the current typical VN provision needs to manually configure the NVE in order to generate the relevant VN. However, in the case that the data center has tens of thousands, or even hundreds of thousands of servers/PCs/virtual machines (VMs) and possibly supports tens of millions of virtual networks, the workload of this manual configuration is huge, thus affecting the development efficiency of the VN service. Furthermore, in the related art, the VM cannot automatically discover the desired NVE and also needs manual operation, which would also greatly affect the development efficiency of the VN service.